Ignore EOFError when reading a truncated pickle file

If the pickle config file is 0 bytes in length,  we may have
crashed (or been aborted) while writing the file out to disk.
Instead of crashing with a backtrace, just treat the file as
though it wasn't present and load off a `git config` fork.

Signed-off-by: Shawn O. Pearce <sop@google.com>

git_config.py

@@ -236,6 +236,9 @@ class GitConfig(object):
         return cPickle.load(fd)
       finally:
         fd.close()
+    except EOFError:
+      os.remove(self._pickle)
+      return None
     except IOError:
       os.remove(self._pickle)
       return None
@@ -414,6 +417,7 @@ def _preconnect(url):
     host = m.group(1)
     return _open_ssh(host, 22)
 
+  return False
 
 class Remote(object):
   """Configuration options related to a remote.

project.py

@@ -733,9 +733,7 @@ class Project(object):
         last_mine = commit_id
         cnt_mine += 1
 
-    if not local_changes and not upstream_gain:
-      # Trivially no changes caused by the upstream.
-      #
+    if not upstream_gain and cnt_mine == len(local_changes):
       return
 
     if self.IsDirty(consider_untracked=False):

subcmds/sync.py

@@ -123,7 +123,8 @@ later is required to fix a server side protocol bug.
   def UpdateProjectList(self):
     new_project_paths = []
     for project in self.manifest.projects.values():
-      new_project_paths.append(project.relpath)
+      if project.relpath:
+        new_project_paths.append(project.relpath)
     file_name = 'project.list'
     file_path = os.path.join(self.manifest.repodir, file_name)
     old_project_paths = []
@@ -135,6 +136,8 @@ later is required to fix a server side protocol bug.
       finally:
         fd.close()
       for path in old_project_paths:
+        if not path:
+          continue
         if path not in new_project_paths:
           project = Project(
                          manifest = self.manifest,
@@ -163,9 +166,11 @@ uncommitted changes are present' % project.relpath
                 break
               dir = os.path.dirname(dir)
 
+    new_project_paths.sort()
     fd = open(file_path, 'w')
     try:
       fd.write('\n'.join(new_project_paths))
+      fd.write('\n')
     finally:
       fd.close()
     return 0
@@ -217,6 +222,10 @@ uncommitted changes are present' % project.relpath
             missing.append(project)
         self._Fetch(missing)
 
+    if self.manifest.IsMirror:
+      # bail out now, we have no working tree
+      return
+
     if self.UpdateProjectList():
       sys.exit(1)